[jQuery] get tag name

<select name="month" id="month" >
<option value="" SELECTED></option>
<option value="1" >January</option>
<option value="2" >February</option>
function do_something_based_on_tag_name(selector) {
if(???=='select') {}
}
var selector = jq('#month');
do_something_based_on_tag_name(selector);
How do I get tag name from "selector" variable?